fix icecream check to not break on SUSE

configure.in

@@ -2179,7 +2179,7 @@ GCC_HOME_SET="true"
 AC_MSG_CHECKING([gcc home])
 if test -z "$with_gcc_home"; then
     if test "$enable_icecream" = "yes" ; then
-        if test -d "/usr/lib/icecc/" ; then
+        if test -d "/usr/lib/icecc/bin" ; then
             GCC_HOME="/usr/lib/icecc/"
         else
             GCC_HOME="/opt/icecream/"